Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

LOCO 2 > Muscles in health and disease > Flashcards

Muscles in health and disease Flashcards

1
Q

What % of body mass are muscles

A

40

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Apart from movement, what function do muscles have

A

Store of intracellular ions like potassium

Important for heat production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens if there is damage to a single motor neurone

A

Affects all muscle fibres innervated by that neuron
80-90% of mass will be lost within the month
Remaining motor neurones will sprout and synapse with denervated fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What determines the fibre type when re-innervation is occuring

A

Primary motor neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens when remaining motor axons sprout to innervate denervated fibres

A

The motor units enlarge and fibres become grouped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In terms of muscles, why may a baby suffer from infantile hypotonia

A

Fibres and small and round wtih a few massivelly hypertrophic fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the underlying pathophysiology of infantile myopathic hypotonia

A
  • Disproportion between the 2 muscle fibres types
  • Type 1 fibres which are usually the large type appear small
  • Type 2 fibres which are usually smaller are normal to larger in diameter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What respiration do the 2 types of muscle fibres undergo

A

Type 1= aerobic

Type 2= both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which fibre type stains darker and why

A

Type 2

ATPase demarks fibres with lots of ATPase, and as anaerobic resp less ATPase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How may muscle disorders be diagnosed

A

Biopsy

EMG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name 2 inflammatory myopathies

A

Polymyositis

Dermatomyositis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is dermatomyositis

A

An autoimmune disorder associated with microbial infection resulting in proximal muscle weakness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What biochemistry results may be seen in dermatomyositis

A

Elevated serum creatine kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What would an EMG of somebody with dermatomyositis show

A

Irritability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What would a biopsy of somebody with dermatomyositis show

A

Variation in fibre size
Central nuclei
Necrosis and regeneration
Infilitrate of inflammatory cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What lymphocytes invade in dermatomyositis

A

CD8 positive cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What inflammatory cells are seen in dermatomyositis

A

CD8 positive cells

macrophages to remove necrotic fibres

18
Q

What is the most obvious physical sign of dermatomyositis

A

Rash– purple and streaky

Heliotrope rash over eye with oedema

19
Q

What is subcutaneous calcification

A

Autoimmune connective tissue disease resulting in calcification of muscles and skin

20
Q

How may subcutaneous calcification be treated (3)

A
  • Corticosteroids
  • Azathioprine
  • Methotrexate
21
Q

Describe the course of corticosteroids prescribed for subcutaneous calcification

A
  • High dose 1mg/kg day

- Maintained until creatine kinase normal

22
Q

What is the 5 and 8 year survival of subcutaneous calcification

A

5 year= 80%

8 year= 73%

23
Q

What causes death in subcutaneous calcification

A

Malignancy, infection, pulmonary involvement

24
Q

What are the signs and symptoms of inclusion body myositis

A

Muscle weakness, specifically in finger and wrist flexors, shoulder abductors and knee extensors
Associated polyneuropathy, dysphagia and loss of quadriceps reflex

25
Q

What is the most common muscle disease of the elderly

A

Inclusion body myositis

26
Q

How do fibres appear in inclusion body myositis

A

Empty vacuoles and clumps of cellular material containing amyloid like material

27
Q

What structures are found in the filamentous inclusion in inclusion body myositis

A 
Beta amyloid
Hyperphosphorylated tau
Apolipoprotein E
Presenilin 1
Prion protein
28
Q

What are muscular dystrophies

A

Progressive genetically linked degenerative myopathies

29
Q

Name some x-linked muscular dystrophies

A
  • Duchenne and Becker muscular dystrophies
  • Limb girdle muscular dystrophy
  • Emery- Dreifuss muscular dystrophie
30
Q

Name some autosomal recessive muscular dystrophies

A

Limb girdle muscular dystrophy

Emery-Dreifuss muscular dystrophy

31
Q

Describe what Duchenne MD is

A

Proximal muscle weakness in first 2 years of life followed by a continuous show decline
Unable to walk by 7-12, death mid 20s-early 30s

32
Q

How many babies are born with Duchenne MD

A

20-30: 100,000 males

33
Q

What are the creatine kinase levels like in babies with Duchenne MD

A

Elevated

34
Q

What would a muscle biopsy of somebody with duchenne MD show

A

Fibre size variability
Endomysial fibrosis
Degenerating muscle fibres undergoing myophagocytosis

35
Q

What happens in the late stages of duchenne MD

A

Loss of muscle replaced by fibrotic material and fat

36
Q

What myopathies can be induced by steroids

A

Type 2 fibre atrophy

37
Q

What myopathy can be induced by statins, and in what % of patients

A

Rhabdomyolysis

38
Q

What are the features of fibromyalgia

A
  • Widespread muscle pain with associated fatigue and sleep disturbance
  • Both sides of the body in axial skeleton
39
Q

50% of fibromyalgia patients are positive for what

A

Antipolymer antibodies

40
Q

What is the normal age and sex of fibromyalgia patient

A 
30-60
Majority female (80-90%)
41
Q

How is fibromyalgia treated

A

Tricyclic antidepressant (amitriptyline)
SSRI (fluoxetine)
Exercise

LOCO 2 (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions